What would cause engine to jam while cranking??

On going problem with getting my 69 Cuda 318,auto, to run.engine ran fine before , engine was a total rebuild, had about 500 miles on it,[ had a cheap Pro Comp dist. and matching coil, it got cooked by bad voltage reg. Have tried a Pertronix dist. and matching coil,[ all new plugs, wires, all voltage are correct ] car would start up, would run rough then die. gave up the Pertronix, have installed a Mopar type electronic ignition, dist., coil, resistor block ,wiring, Per instructions, put engine to 10 deg. before tdc, made sure rotor is pointing at #1 , double checked plug wire firing order, when cranking, engine seems like it is jamming, it will crank normal, then stop/jam , did not want to keep trying it, went to remove the + battery cable it was very warm never noticed that with the Pertronx, it seems like the starter is drawing a lot of amps, again did not have any type of issue with the Pertronx. tried to adjust timing at dist, does/did not change the way the engine is cranking, and no start.

Maybe I should just go back to a points system?